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® All rights reserved. The owners of this website assert their right to restrict the use of the trademark SIREMAX® to sheep that have continually updated records in the SIREMAX® database and the LAMBPLAN database.

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We are now listing Rams for Sale in two ways. To find a list of rams available from a particular flock, first click the link below and then the Ram Sale List button on the flock page.

Southeast Minnesota | Southwest Minnesota | Montana | Oregon

You will find a combined list of all the rams for sale by clicking here. All the lists are printable PDFs and rams are listed in order of their Carcase Plus index ranking.

We try to keep these lists up to date, but we cannot guarantee that all the rams listed are still available. Please contact us to check.

We could also provide lists of rams ranked by Post Weaning Weight EPDs and Post-weaning Eye Muscle Depth EPDs, if this sounds more useful. Let us know about that.


Selecting breeding sires is our most important activity, whether the rams are intended for our use or for sale.

The activities that we engage in can be called genetic technology, that is the time spent identifying sheep, setting up breeding groups, assembling data, conducting Lambplan analysis etc.. This genetic technology is based on a branch of science called population genetics - the study of genetics in groups of animals; small groups and large groups.

The technology that Siremax uses is primarily concerned with improving the average performance of the whole Siremax flock, and each new lamb crop. We do identify top ewes, rams, and lambs whenever we sort by index or trait, and we identify the bottom end too. However, we are not in the business of making elite sheep, or seeking blue ribbons for 'best-in-show'.

What we do is illustrated best by this edited extract from the Lambplan Breeder's Guide. The complete Breeder's Guide can be found online here.

In 2010 Siremax doubled the number of its flocks from two to four, and we expect to add three more Siremax flocks in three or four years, and a number of upgraded flocks. These developments will bring both changes and opportunities.

We raise lambs at several locations, but we submit data to LAMBPLAN in one submission or dataset. This requires Siremax as a ‘breed’ to employ the same high degree of technical and analytical discipline throughout the organization.

The quality and accuracy of our data, and subsequent sire selections, determine our rate of genetic improvement. The effort we put into linking our flocks, creating the best possible breeding groups, and maintaining our sirelines, determines the content, diversity, and even distribution of our genepool.

We run 14 sirelines and prefer to use ram lambs when we can. So we try to keep each of our breeding groups at around 20-25 ewes, evenly matched by age.

One change this requires is that we must expand our efforts to link all our flocks. Exchanging rams between flocks each year to ensure this linkage, and to ensure that each flock has the ram power to use at least half the sirelines each year, takes a lot of rams. This is especially the case when you know that we must have back-up rams on hand in case of disability or death.


We always select our flock sires by index ranking, and we sell commercial terminal sires the same way – priced according to predicted performance.

If you look at the rams available in Oregon, Montana and Belview MN now, you might think we are short of high indexing rams. This is because we are forced to ‘bank’ more rams than usual while the new franchise flocks come on stream. This situation should straighten out within a year. In the next round of expansion we will need to consider linking the flocks by artificial insemination.

We are sometimes asked if we have doubled the performance of the Siremax flock, since our average index is now right about 200. No, it doesn’t work that way. The Carcase Plus index we use is like a Relative Feed Value, a number designed to combine multiple trait values in a way that enables us to make the best possible selection decisions. (Relative Feed Value helps you value and compare quality in feedstuffs, like hay).

We select the best ram lambs for our own use, the next best we sell to commercial lamb producers. However, our goal is to improve the average performance of each new lamb crop in each of our measured index traits.


The Carcase Plus index has served us well over the last 17 years, but we are ready for the change coming in 2011. The PWWT component will be ratcheted up from 60% to 65%. PFAT drops from 20% to 5%. PEMD soars from 20% to 30%.

Let’s take these one at a time:

1. The small increase in PWWT acknowledges the primacy of growth in returning profit to producers.

2. Many breeders believe that we have done enough in lowering PFAT; some believe we may have gone too far. Nonetheless, we have found a comfortable level and more will be accomplished with careful lamb marketing. The 5% emphasis on PFAT is calculated to keep the current level of performance in place for the next ten years.

3. Obviously the big change will be the 50% increase in emphasis on PEMD, Ribeye Depth. U.S. lamb processors have been clamoring for more muscle in their lambs, and producers will now have a better tool to deliver that. Remember, the genetic correlation between PWWT and PEMD is neutral at best. LAMBPLAN has said that it is a weak negative, and NSIP has said that it is a stronger negative. In other words, our single focus on ‘rate of gain’ has likely decreased muscle in U.S. lambs. It is maximized gain, tempered by positive EPDs for PEMD, which will ensure lean growth. Ask for it.

Siremax guarantees the good health of the rams they sell for thirty (30) days after the date of delivery, or until these sheep are commingled with other sheep after the date of delivery, whichever comes first.

Siremax guarantees that the rams listed will make healthy ewes pregnant in the first six (6) months after delivery, and will reimburse the full price of a ram that fails to breed after a salvage value and selling costs are deducted. Failure to breed must be verified by semen evaluation by a licensed veterinarian. On no account will Siremax take back a non-performing ram.

Siremax makes no claim for the performance of the progeny of Siremax rams except that the genetic value expressed as EPDs and indexes are honestly calculated and represented.

Siremax will arrange for health certification, as required by individual states, which will be billed at cost. Other tests and certification can be arranged upon request.

The owners of this website assert their right to restrict the use of the trademark SIREMAX® to sheep that have continually updated records in the SIREMAX® database and the LAMBPLAN database.

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